http://nhatanh.voxfamilyvn.com/moo/calendar.html

code snipped from calender.js:
==================================================
if(!this.opt.auto_show) {
			y = $(this.opt.p_name).getOffset('top')  + 5;
			x = $(this.opt.p_name).getOffset('left') + 5;
			_1.setStyle('position', 'absolute');
			_1.setStyle('top', y + 'px');
			_1.setStyle('left', x + 'px');
			_1.setStyle('z-index', '1000');
			this.opt.position = 'before';
		}
==================================================
The getOffset values are correct for the image, but
when it is displayed as:

<d_1_e style="display: block; visibility: visible; opacity: 1; position: absolute; top: 405px; left: 470px; z-index: 1000;" class="c_all" id="d_1_e">

That is also correct, but the calender takes the absolute edges of the Tab and not of the viewport?!